AC induction motors and other multiphase electrical loads are often driven by a multiphase inverter providing AC output voltages and currents to the driven load. Degradation or faults in motor windings can contribute to motor failures or degradation of the driven motor load and/or the power source. Accordingly, detection of the onset of motor winding degradation and other load faults can be useful for proactive maintenance to avoid or mitigate the onset of overheating and/or stator winding insulation breakdown and the like.